Qt 中集成mqtt协议的使用方法

#ifndef mqttmanagert_h
#define mqttmanagert_h
#include <iostream>
#include <mqtt/qmqtt.h>
class mqttmanager:public qobject
{
    q_object
    q_property(qstring intemperature read getintemperature write setintemperature notify intemperaturechanged final)
    q_property(qstring inhumidity read getinhumidity write setinhumidity notify inhumiditychanged final)
public:
    static mqttmanager* instance();
    qstring getintemperature() const;
    void setintemperature(qstring newintemperature);
    qstring getinhumidity() const;
    void setinhumidity(qstring newinhumidity);
private:
    ~mqttmanager();
    mqttmanager();
public slots:
    void doconnected();
    void onsubscribed(const qstring& topic);
    void dodisconnected();
    void dodatareceived(qmqtt::message message);
signals:
    void intemperaturechanged();
    void inhumiditychanged();
private:
    qmqtt::client *client;
    static mqttmanager *manager;
    qstring intemperature;
    qstring inhumidity;
};
#endif // mqttmanagert_h

#include "mqttmanagert.h"
mqttmanager* mqttmanager::manager=nullptr;
const qstring host= "127.0.0.1"; //服务器地址
//需要订阅的主题
const qstring topic_in_temperature_humidity ="qmqtt/in_temperature_humidity";
mqttmanager::mqttmanager(){
    client = new qmqtt::client(qhostaddress(host),1883,this);
    connect(client,&qmqtt::client::connected,this,&mqttmanager::doconnected);
    connect(client,&qmqtt::client::disconnected,this,&mqttmanager::dodisconnected);
    connect(client,&qmqtt::client::received,this,&mqttmanager::dodatareceived);
    connect(client, &qmqtt::client::subscribed, this, &mqttmanager::onsubscribed);
    client->connecttohost();
}
mqttmanager::~mqttmanager(){
    client->disconnected();
}
mqttmanager* mqttmanager::instance(){
    if(!manager){
        manager = new mqttmanager();
    }
    return manager;
}
void mqttmanager::doconnected(){
    qdebug()<<"doconnected ok";
    //再此订阅主题
    client->subscribe(topic_in_temperature_humidity);
}
void mqttmanager::onsubscribed(const qstring& topic)
{
    qdebug() << "onsubscribed " << topic;
}
void mqttmanager::dodatareceived(qmqtt::message message){
    //收到消息
    qstring mes = qstring(message.id())+" "+qstring(message.qos())+" "+message.topic()+" "+message.payload()+"\n";
    qdebug()<<"datareceived "<<mes;
   //根据主题过滤消息
    if(message.topic()==topic_in_temperature_humidity){
        qstringlist datalist = qstring(message.payload()).split(",");
        if(datalist.size()==2){
            setintemperature(datalist[0]);
            setinhumidity(datalist[1]);
        }
    }
}
void mqttmanager::dodisconnected(){
    qdebug()<<"dodisconnected ok";
}
qstring mqttmanager::getintemperature() const
{
    return intemperature;
}
void mqttmanager::setintemperature(qstring newintemperature)
{
    if (intemperature == newintemperature)
        return;
    intemperature = newintemperature;
    emit intemperaturechanged();
}
qstring mqttmanager::getinhumidity() const
{
    return inhumidity;
}
void mqttmanager::setinhumidity(qstring newinhumidity)
{
    if (inhumidity == newinhumidity)
        return;
    inhumidity = newinhumidity;
    emit inhumiditychanged();
}